The present invention relates to a tissue adhesive and a delivery system for applying the same. More particularly, the tissue adhesive is comprised of a first solution containing fibrinogen and a second solution containing thrombin. The apparatus is used to keep these two solutions separate until they are applied together at a treatment site to seal a wound, stop bleeding or the like.
Fibrin glues and adhesives have been known for many years. For example, U.S. Pat. No. 2,533,004 which issued on Dec. 5, 1950 to John D. Ferry discloses various methods for making fibrin clots using different concentrations of fibrinogen solution in conjunction with the thrombin solution.
Similarly, various types of applicators for fibrin glue solutions are disclosed in the prior art. For example, U.S. Pat. No. 4,359,049, which issued on Nov. 16, 1982 to Redl, et al, discloses a syringe-type apparatus for applying a tissue adhesive. The apparatus disclosed in the Redl patent includes a plurality of standardized one-way syringe bodies of synthetic material. Each syringe body accommodates a plunger and ends in a coni. The apparatus also includes a means for holding the various syringe bodies together, a guide rod, common actuating means associated with the guide rod and the plungers, and a collecting head connecting the coni of said syringe bodies.
The design of the Redl patent, however, is lacking for several reasons. First, the connecting head brings the two materials together and the materials then travel together through a single mixing needle. Because the materials are so quick to form a bond, this arrangement can cause the apparatus to become clogged and unusable. Second, the apparatus of the Redl et al fails to provide a means by which the apparatus can be gripped comfortably in a variety of orientations. Thus, it is not as easy to manipulate as may be necessary for use in certain surgical procedures.
The Eibl et al 4,735,616 patent which issued on Apr. 5, 1988 describes another arrangement for applying a tissue adhesive. The applicator of Eibl et al is quite similar to the applicator of Redl et al discussed above and, therefore, is subject to the same deficiencies. The primary differences between the Eibl et al and Redl et al disclosures is that the Eibl system includes one syringe body that has a cross-sectional area that is two to nine times larger than the cross-sectional area of the remaining syringe bodies. This permits disproportionate amounts of the solutions within the syringe bodies to be dispensed simultaneously. This same feature for this same purpose is also taught in U.S. Pat. No. 4,040,420 to Speer. Also, the Eibl patent discloses bypass means associated with the syringe bodies.
The Speer patent also discloses an embodiment that would help avoid the clogging problems of the Eibl et al and Redl et al patents. However, the apparatus disclosed in the Speer patent would be far more clumsy to work with than the present invention. This is particularly true when the apparatus is to be used in micro surgical procedures such as in the middle or inner ear. Speer, like the other references, fails to teach an acceptable applicator which is comfortable to hold in a plurality of orientations and, therefore, easy to manipulate.